Combined drill and reamer



.|.'P. FULLILDVE. COMBINED DRILL AND REAMER. APPLICATION FILED JUNE 22. 1920.

Patented Apr. 4, 1922.

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a ATTORNEY.

Y L. P. FULLILOVE.

COMBINED DRILL AND REAMER. APPLICATION FILED JUNE 22, 1920.

1,411,484, I a Patented Apr.4, 1922.

2 SHEETS-SHEET 2.

lNVENTOR ATTORNEY.

UNITED STATES JOHN P. FULLILOVE, OF SHREVEI'ORT, LOUISIANA COMBINED DRILL AN D REAMER.

Specificationof Letters Patent.

Patented Apr. 4, 1922.

Application filed June 22, 1920. Serial No. 390,750.

To all whom it may concern:

Be it known that I, JOHN P. FULLinovn, a citizen of the United States, residing at Shreveport, Louisiana, have invented certain new and useful Improvements in a Combined Drill and Reamer, of which the following is a specification.

This invention comprises a combined drillbit and reamer. lVhile its application is unrestricted, it is especially adapted for use in the drilling of oil and gas wells and the like.

It is contemplated among the objects of the invention to provide a combined drillbit and reamer, the reamer comprising a blade or plurality of blades normally housed within the outer walls of the drill-bit and so arranged that they may be forced outwardly beyond the plane of the wall of the bit-head to enlarge or undercut the hole made by the bit.

It is also contemplated to arrange the reaming instrumentality so that the pump and pressure medium ordinarily used in connection with a well drilling rigrnay be utilized as a means for outwardly extending the reamers; to so arrange ducts, channels and chambers for the pressure medium that when the reamers arrive at a predetermined position of extension there will be a pronounced change in the pressure which may be used as an indication that such predetermined position has been reached; also, to so house the reamers within the bit-head that they will form practically an integral part of it when closed and even when opening will be unaffected by the jarring, will have no openings within which foreign matter may lodge, and will have a positive bearing under all conditions at a plurality of points within the bithead.

The pivoting of the reamers at the upper portion of the drill-bit so that withdrawal of the bit from the hole will close the reamers; the shape of the reamer blades; the ar rangement of the pressure ducts and chambers to roduce a flexibility of the reamer blades w ich permits themto conform with irregular wall surfaces; and the simple, practical arrangement of the parts for assemblage, are features of the invention which will in part be apparent and in part be brought out more fully in the description which follows.

Drawings illustrating an embodiment of the invention are appended, and in these blades.

Figs. 1 and 2 are views in front elevation showing an embodiment of the invention with parts in two positions;

Figs. 3, 4L and 5, are views in transverse section on lines 3-8, 44=, and 55, respectively;

Figs. 6 and 7, are views in central ver tical section and seen from the front and side respectively.

a In these views, 1 designates a drill-bit or bit head, provided with a cutting edge 2 at one end, and at the other end secured to a pipe 3. This pipe is in communication with a source of pressure medium and forms a part of a drill stem not shown.

The body portion of this head is preferably made in two parts suitably secured together when assembled, as by bolts or the like 4. Each section is hollowed out on the inside face thereof to constitute a chamber 5, or compartment within which there is housed a plurality of reaming instrumentalities 6.

These reamers comprise blades having tapered or beveled edges 7 to constitute cutting edges and are hung from a pivot 8 at the upper portion of the drill bit. The upper portion of each blade is rounded in the shape of an arc of a circle with'the pivot 8 as a centre and the upper portion of the chamber 5 is correspondingly shaped. The lower portion of each chamber is shaped to conform with the lower portion of each blade, thus providing a double bearing for the blade which is supported on the pivot 8, and the lower portion of the --chamber. These blades are disposed face to face within the chamber or compartment 5 and normally housed therein. The chamber is provided with openings through which the blades may be extended as shown, the arrangement being such that the outer edge of each blade constitutes practically a continuation of the corresponding edge of the drill bit when the blade is in closed position. This prevents the entrance of any foreign matter to the chamber and insures free working of the A packing 9 may also be provided around the edges of the openings through which the blades are extended, and at the upper portion of each blade there is a means for limiting its outward movement, the same here comprising a shoulder 10 adapted to bear against the upper edge of the opening when in extended position.

' Means are provided for extending the tion of the reamers.

blades outwardly to undercut or enlarge a drill hole, and to this end there are shown channels 11 in the head oi the drill bit.

These are in communication at one end through pipe 3, w1th a source ctpressure medium and at the other end communicate with the chambers?) at the back .edge of each blade. It will be Understood that by leading the pressure fluid back of the blade the latter will be forced outwardly until limited by the shoulder 10. V

Means are provided whereby the pressure acting on the back of the blades will be automatically graduated so that while less at the beginning of the movement of the blade, it will be increased in direct proportion at a predetermined rate in proportion to the distance the blade is extended from the side of the bit. As here shown, this is'eilected by providing the circular portion of each blade, at the point where it would cross one of the ducts 11, with a cut away-portion 12, hollow in cross section as shown in Fig. 5, and restricting the opening when in closed position, but gradually enlarging as shown in Fig. 6, until, at its largest portion it gives an unrestricted passage for ressure medium through the channel 11.

cans are'provided for indicating when the pressure medium has forced the blades outwardly to a predetermined position and .for providing free passage of the pressure medlum into the hole afterthis point has been reached.- As here shown this is efiected by providin openings 13 in the side of the drill bit and openings 14 in theouter portion of each blade, so arranged as to be in communication with the openings'13 when the blades are in extended position. The

inner ends ofthe openings 14 arein-rommunication with larger ports 15 in each blade andso arranged that when the blades are extended as shown in Fig. 5, there will be free access between the channels 11 back-of each blade and through the ports and openings with the drill hole. It will be apparent that when this point is reached there will be a sudden falling off of the pressure medium dueto the opening of the ducts, which may be utilizedin changing the posi- In actual use the pressure is kept at a maximum: capacity of the pump until thepredetermined position of the blades is reached,

or when channels 15 are in communication. l his is arranged so as to be the extreme extension of the blades.

At this point the re lease of'pump pressure willindicate to the operator that the blades are in full openposition. This givesflpositive information of this fact as'thei'e will be no release until both bladeshave reached, full extended position. Opening, of one blade only will not-effects re ease of the pump pressure. r

Byarranging the retainers in the-.manner shown, there is a completely closed drill head with no openings into which foreign matter can enter to interfere with the working of the'parts. The openings 12-3 are c0mparatively small, situated in a position where there is slight liability of picking up any foreign matter and the pressure medium be ing back of these openings will drite out anything that may lodge there.

The blades being pivoted at the upper portion of the drill bit may be easily closed by merely withdrawing the bit so that the blades are forced inwardly by the restricted neck of thehole or the casing which may incertain instances be employed. While the iniention is disclosed in the embodiment herein described, it will be under stood that I do not wish to be limited to the precise form of this disclosure, as many changes maybe made in the construction and general arrangement of the parts without departing fromthe spirit of the invention or its scope as set forth in the claims.

hat I claim is 1 1. A reamer comprising-a body having a chamber and channels'for the passage of fluid under pressure, bits pivoted within said chamber and having ducts-(graduallyyincreased in depth from one en whereby the passage of the fluid under pressure through said ducts from said channel forcessaid bits outwardly.

2. A reamer comprising a body having a chamber and channels for the passage of fluid under pressure, bits pivoted within said chamber and having ducts gradually increased indepth from one end whereby the passage of-fluid under pressure through said ducts from said channels 'forces'said bits outsaid bits.

A ream'er comprisinga body having a chamber and channels for the' passage of fluid under pressure, bits pivoted within said chamber and having ducts gradually increased indepth from one end whereby the passage of fluid under'pressure through said ducts from said channels forces said hits outwardly, the walls of said chamber being provided with openings adapted to beclosed by said bits, said bits being provided with openings adapted for registration with the openings in said channel.

4. A reamer comprising a body having a chamber-and channels communicating with the chamber and adapted for the passage of fluid under pressure, bits pivoted within said by i the pressure of the fluid passing through said ducts.

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